Question

If f:R->R is defined as f(x)=x²-3x+2 .

Find f(f(x))

Answer 1

Given that, f(x)=x2−3x+2
∴f{f(x)}=f(x2−3x+2)=(x2−3x+2)2−3(x2−3x+2)+2=x4+9x2+4−6x3−12x+4x2−3x2+9x−6+2=x4+10x2−6x3−3xf{f(x)}=x4−6x3+10x2−3x